The use of desktop computers has grown dramatically since the introduction of the personal computer in 1981. An estimated 75% of all workers are sedentary, and many of those use personal computers as a part of their jobs. In addition, schools, colleges, libraries and other institutions have invested heavily in electronics to keep their communities current with the latest technologies and information sources.
Unfortunately, many of these computers are situated on furniture that was not designed either to support the computer hardware or to promote a healthy interface between the machines and the operators.
The standard height of worksurfaces on desks is 29 to 30 inches. The most common configuration of a desk for office work is a unit at that height, having two 15 inch inch wide pedestals for 11 inch paper filing, and a 28 inch wide knee space that includes a center drawer for storing small office supplies. The typical stand-alone desktop computer requires space for a monitor, a central processing unit, keyboard, a computer mouse or trackball, a printer and a side assortment of add-on peripherals and accessories. All of this hardware robs the individual worker of space so important for effectively and comfortably performing normal workplace tasks. More important, the input devices--the keyboard and computer mouse being the most popular--are too frequently placed on top of the 29-30 inch high work surface. This placement forces an operator's arms, hands, shoulders, and back into postures that are unnatural and frequently uncomfortable. If these postures are repeated over several hours each day for a period of months or years, an operator may experience symptoms ranging from mild discomfort through chronic pain to disabling injury.
The human and economic costs of unhealthy postures and repetitive strain injuries have been widely documented in corporate, scientific, and governmental literature. The Federal government, acting through the Occupational Safety and Health Administration is preparing Ergonomic Protection Standard that would apply to computer use in the workplace. It would set performance-oriented guidelines. At the earliest date, they would go into effect in 1996. Absent a Federal guideline, many organizations have begun concerted efforts to make their office environments more ergonomically sound.
Office furniture and office product manufacturers have offered a wide variety of products that are marketed as ergonomic. Many of these items fail to meet any of the criteria for ergonomic soundness, and some even worsen the situation by encouraging operators to assume unhealthy postures. Some contract furniture manufacturers offer adjustable-height tables and desks, and adjustable keyboard and computer mouse supports. Unfortunately, the price of most of these items puts them out of reach for millions of workers. All too often, the primary factor determining whether or not to buy a computer accessory or computer furniture is the purchase price. A buyer's perception of achieving greater comfort, as suggested by the marketing efforts of the manufacturer or distributor, often leads to the purchase of items that turn out to have little or no positive effect.
One basic requirement for supporting healthy body postures for operators using a keyboard and a computer mouse is that the keyboard support that holds these devices includes swiveling, tilting, and height adjustment mechanisms. A height adjustment places the keyboard support between 22 inches and 27 inches above floor level in order to promote an upper extremities neutral posture for 95% of the U.S. population. The negative side of the keyboard support tilt compensates for the positive tilt built into keyboards. A negative tilt of 23.degree. allows most standing operators to input with wrist neutrality when the computer is placed on desk height (29-30 inch) furniture. Tilting mechanisms also provide an option of a small positive tilt to allow operators who prefer that inclination to continue keying in a manner that is both comfortable and efficient for their keying habits. It also allows users of notebook computers to position their bodies comfortably while maintaining wrist neutrality. Swiveling mechanisms allow operators to position their bodies, keyboards, and computer mouses in alignment with monitors that are located in a corner of the work station.
Since computers are often used by various people throughout the day, it is essential that the platform support a rapid, easy transition for left- or right-hand mouse (or trackball) users. Also, there should be an area large enough to support a person's hand and forearm. This area is used for resting between mouse operations to preclude resting one's arm weight on the mouse and prevent the resultant static clenching posture of one's hand gripping the mouse.
Some prior art combinations of a support for a keyboard and a computer mouse and a storage area for small office supplies are discussed below.
The Snapease line by Rubbermaid allows the computer mouse to be placed to the left or the right of the keyboard, and space is provided for supplies. The keyboard supports are either 42-46 inches wide and are designed for use only with a Rubbermaid desk. The keyboard and computer mouse support does not tilt or adjust for height with the negative result that it does not promote healthy neutral postures for operators of various sizes.
The Aurora keyboard support system by Ergonomic Environments offers a model that provides keyboard and computer mouse support within a 27.5 inch overall width. The unit is tilt and height adjustable. But it provides no storage for supplies. Moreover, it does not promote healthy mousing postures, because the computer mouse support is not deep enough to act as a forearm rest between mousing episodes.
The Flex Rest manufactures a keyboard drawer that is tilt and height adjustable which includes a pivoting computer mouse tray and pencil tray. The unit tilts only negatively, thereby failing to accommodate the needs of users who prefer a positive slope. The computer mouse tray is too shallow for forearm support. The storage area is minimal. The unit is too wide to fit in the 28 inch knee space of a conventional 60 inch by 30 inch desk.
Rubbermaid also manufacturers computer mouse platforms, that attach to several of its under-desk keyboard drawers, as disclosed in U.S. Pat. No. 330,892. The drawers have small hinged compartments for pencils, clips, and so on. The drawers are not height and tilt adjustable, and the computer mouse platform is very shallow.
Global Computer Supplies offers two related items. The first is a keyboard support that starts at desk height which can be lowered in three increments to 3.75 inches below the work surface. It has a small storage area for supplies and an optional computer mouse tray that attaches left or right. The unit has no tilt adjustment, and the 3.75 inch computer mouse adjustment below the top of the work surface is not sufficient to promote wrist neutrality for 95% of seated operators. The second item tilts plus/minus 15.degree. and adjusts from 2.75 inches to 5 inches below the worksurface. The 2.25 inch height adjustment range does not allow neutral postures for many operators. Also, because the unit is mounted on ball bearing slides rather than to an articulating arm, it is cumbersome to adjust the height once the unit is installed.
Manufacturers such as Details, Knoll, Haworth, Herman Miller, Proformix, and Ergo Systems offer several keyboard supports. Both Details and Proformix have additional computer mouse supports that can swivel and tilt. But none provide supply storage that allows the operator to discard the desk center drawer and retain adequate under-desk storage volume.
Prior art also reveals attempts to solve one or more ergonomic issues associated with wrist supports for keyboard operators. Some such patents are as follows:
U.S. Pat. No. 5,273,250 discloses a forearm resting member that is substantially coplanar with the top surface of the keyboard apparatus.
U.S. Pat. No. 5,244,296 discloses an edge portion elevated to a level substantially above the immediately adjacent keys to maintain proper wrist angle during keyboard use. The elevated region of the edge portion is parallel to the planar surface of the keyboard housing.
U.S. Pat. No. 5,228,655 discloses a wrist rest on which both wrists are supported that is higher than the top of the keyboard. One purpose of the wrist support is to maintain an angle between the wrist and the hand while typing that minimizes strain on the wrist thereby preventing repetitive motion strain syndrome.
U.S. Pat. No. 5,131,614
U.S. Pat. No. 5,147,090
U.S. Pat. No. 5,188,321
U.S. Pat. No. 5,219,136
U.S. Pat. No. 5,244,296
Prior art patents also reveal apparatuses for adjusting supports for computer keyboards. Some such patents are as follows:
U.S. Pat. No. 4,616,798
U.S. Pat. No. 4,913,390
U.S. Pat. No. 5,037,054
U.S. Pat. No. 5,257,767
U.S. Pat. No. 5,351,897
U.S. Pat. No. 306,239
The present art of computer keyboards includes a typical keyboard having a planar keyboard bottom surface and parallel operator-proximate and operator-distal keyboard edges. The keyboard typically includes five rows of keys respectively located proximate to distal from the operator all of which are spaced at the same distance from the keyboard bottom surface 14 further includes a distal rear key row aligned in parallel with the other four key rows having keys spaced from keyboard bottom surface at a very slightly greater distance than are the keys of the other key rows. Each key has a horizontal top surface that includes an operator-proximal top edge and a parallel operator-distal top edge. The typical keyboard forms a substantially planar keyboard top area particularly defined by the operator proximal top edges of all the keys. The planar keyboard top surface is spaced at a greater distance from the keyboard bottom surface at the operator-distal keyboard top area than at the operator-proximal top area, so that the keyboard top surface and the keyboard bottom surface define therebetween an angle typically of approximately 8.degree. that would be imaginatively formed at a pair of intersecting planes located more operator proximate than the operator proximate keyboard edge. The top individual surfaces of each key define horizontal surfaces in a single plane in each succeeding row of keys with each succeeding row of keys forming a horizontal plane stepped higher than the horizontal plane defined by the previous row of keys.